Mycobacterium tuberculosis (M. tb) infects one third of the world's human population1. The common tuberculosis (TB) vaccine known as the BCG vaccine is given to neonates in developing countries. While this vaccine protects against meningeal and disseminated TB in children, it fails to adequately protect the establishment of latent TB or reactivation of pulmonary disease in adult life2. Moreover, BCG effectiveness is reported to decline over a period of 10-15 years3. The most common type of tuberculosis disease is pulmonary and transmission occurs via aerosol droplets expressed during coughing. Thus, despite the high prevalence of BCG vaccination, the disease burden has not decreased. There is now evidence to support that M. tb mycobacterial lineages may have adapted to mutations in antigens common to both M. tb and BCG4,5. Moreover, recent studies suggest that BCG delivered parenterally may fail to induce T-cell immune responses in the lung mucosa, which may be critical for protection against pulmonary disease6,7. Given these reasons, a new vaccine is imperative to decrease the prevalence of TB throughout the World.